The invention relates to improvements in rotary worm centrifuge separators, particularly of the solid bowl type having an independently rotatable worm therein wherein a slurry fed to the centrifuge is separated in a solids fraction and a liquids fraction.
More particularly, the invention relates to an improvement in the structure for the discharge of the liquid fraction.
Adjustable weir plates are provided at liquid discharge openings arranged in the end wall of the centrifuge drum. A ring seal is arranged in the region of the liquid discharge openings between the worm supporting member of the conveyor worm and the centrifuge drum. The ring seal is constructed of two rings wherein one ring seal is supported on and is rotated with the centrifuge drum and the other ring seal is joined to the conveyor worm to rotate therewith. The ring seal rotating with the conveyor worm is provided with anti-wear protection at its annular surface facing toward the liquid discharge openings.
In worm centrifuges of the type above described which have heretofore been known, a collecting space is provided for the liquids separated from the solids which forms during the operation of the centrifuge. This liquid collects between the outer weir plate arranged at the end wall of the drum and the ring seal which is arranged at the worm supporting member of the conveyor worm. This collecting space is sealed from the separating space by a ring seal. It has proven to be unavoidable that the deposits of solids in the liquid collecting space arise during the course of operation of the centrifuge. These deposits cause increased wear at the ring seal arranged at the worm supporting member which rotates at a speed different than that of the centrifuge drum. This wear at the seal ring can lead to leaks in the ring seal so that part of the liquid not yet separated from the solids can proceed from the separating space of the drum into the liquid collecting space. The separating power then is deteriorated or detracted from as a result of this wear. This results in the necessity of the operator removing the worm supporting member from time to time to replace the seal ring. This involves comparatively substantially great outlay in terms of work, time and cost since the drum must be opened for this purpose and the worn seal ring must be removed or must be replaced by a new one.
It is accordingly an object of the present invention to provide an improved centrifugal drum separator structure which has the capability of avoiding the wear at the seal ring of the ring seal which is located between the conveyor worm at the liquid discharge region of a worm centrifuge.
A still further object of the invention is to provide a structure wherein if wear occurs in the seal ring, then the structure is so arranged that the worn parts can be quickly and easily removed and replaced without necessitating the substantial disassembly and work which was necessary in structures heretofore available.